ADU Regulations in Thousand Oaks, California (2026)

Regulations at a glance

Local rules & notes

Three-Unit Combination Requirement: The city must allow a combination of one converted ADU, one detached ADU, and one JADU on a single-family lot. Invalidity of Private Deed Restrictions: The city cannot prohibit ADUs based on private recorded deed restrictions or CC&Rs. Multifamily Height and Size Mandates: The city's 16-foot height and 800-square-foot size limits for multifamily ADUs are non-compliant with state law.

For the official ordinance and latest updates, check your city or county planning department.

Frequently asked questions about ADU regulations in Thousand Oaks

• What is the maximum ADU size in Thousand Oaks, California?

  In Thousand Oaks, the maximum ADU size is typically 800 square feet, depending on whether the unit is attached or detached. California state law allows up to 1,200 sq ft for detached ADUs and 800 sq ft for attached in many jurisdictions; Thousand Oaks may follow state defaults or have local limits. Verify with Thousand Oaks planning for your specific lot.

• What are the setback requirements for ADUs in Thousand Oaks?

  In Thousand Oaks, typical setback requirements are 4 feet from the side property line and 4 feet from the rear. These may be reduced to 4 feet under California Government Code § 65852.2 where applicable. Check with Thousand Oaks planning for overlay zones or design standards that could affect your site.

• What is the maximum height for an ADU in Thousand Oaks?

  In Thousand Oaks, the maximum height for an ADU is generally 16 feet. State law often allows up to 16 feet for detached ADUs and up to 25 feet when within 4 feet of the property line in some cases. Confirm with Thousand Oaks or county planning for your zone.

• Is ADU approval ministerial in Thousand Oaks?

  In Thousand Oaks, ADU approval is typically Ministerial (by-right) per Gov Code §65852.2. Ministerial (by-right) review means the city must approve qualifying applications without discretionary review, per California Gov Code § 65852.2. Your project must still meet objective standards; Thousand Oaks planning can confirm the exact process.

• Are there parking requirements for ADUs in Thousand Oaks?

  In Thousand Oaks, parking for ADUs is generally Often waived per state law; check local ordinance. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with Thousand Oaks planning for your address.